Cyclic oxidation resistance of Ce/Co modified aluminide coatings on nickel base superalloys

• Ce/Co modified aluminide coatings were prepared by pack cementation method.
• Ce content in coatings increases and then decreases with increasing CeO2 content.
• Resistance for cyclic oxidation increases with increasing Ce content in coatings.
• Ce addition improves adhesion of oxide scales by reducing voids and forming pegs.

Ce/Co modified aluminide coatings with different CeO2 content were prepared on nickel base superalloys by pack cementation method. The microstructure and cyclic oxidation behavior of the coatings were investigated. The results show that the Ce addition is beneficial to improving adhesion of oxide scales by forming the “oxide pegs” structure and reducing voids at the scale/coating interfaces. When the content of CeO2 addition in the pack mixture is 2 wt.%, the Ce/Co modified aluminide coating has the highest content of Ce in the outer layer and exhibits the best cyclic oxidation resistance at 1323 K.

The Co–Al–Ce coatings exhibit superior cyclic oxidation resistance to the Co–Al coating and the substrate. The weight change of the Co–Al–Ce coatings with CeO2 addition of 1, 2 and 3 wt.% reaches −3 mg/cm2 after cyclic oxidation for 380 cycles, 1480 cycles and 1410 cycles, respectively.Figure optionsDownload as PowerPoint slide